Adachi (足立区; -ku) is a special ward located in the northern part of Tokyo, Japan. The ward is separated into two areas: one between Sumida River and Arakawa River and one at north of Arakawa River.
The ward is bordered with cities of Kawaguchi, Hatogaya, Soka and Yashio in Saitama and Katsushika, Sumida, Arakawa and Kita in Tokyo.
As of 2003, the ward has an estimated population of 621,848 and the density of 11,688.87 persons per km². The total area is 53.20 km².